configure error

Hi, I downloaded rlib-1.3.6 onto a FreeBSD 5.4 machine and ran the following:

./configure --with-pythonver=2.4 --without-postgres

And it chokes looking for iconf.h.  Here're the last few lines of my output:

Checking for a Python interpreter with version >= 2.4... python
checking for python... /usr/local/bin/python
checking for python version... 2.4
checking for python platform... freebsd5
checking for  script directory... ${prefix}/lib/python2.4/site-packages
checking for  extension module directory... ${exec_prefix}/lib/python2.4/site-packages
checking for perl... /usr/bin/perl
checking iconv.h usability... no
checking iconv.h presence... no
checking for iconv.h... no
configure: error: cannot find iconf.h

Anyone have any ideas on where I can go from here?  I tried to see if installing iconv (via ports) would work, but it didn't help.